The fundamental hypothesis of the organizers of this conference is that progress in the field of osteoimmunology, which is the study of the interactions of bone, hematopoietic and immune cells in health and disease, will be delayed unless better communication is established between bone biologists, hematologist and immunologists. The goal of The Fourth International Conference on Osteoimmunology: Interactions of the Immune and Skeletal Systems is to bring together scientists from these fields in a setting that will facilitate interactions and new collaboration and hasten progress towards understanding the interconnections of the immune, hematopoietic and skeletal systems. Our three previous meeting were fully subscribed and considerable successes. One hundred forty to one hundred fifty participants from all over the world attended each. Three specific aims are proposed: Specific Aim 1 Bring together a faculty of invited speakers who are internationally recognized for their high level of scientific achievement and areas of scientific focus that span the diverse field of osteoimmunology. Specific Aim 2 Structure the conference to promote interactions among all investigators including invited speakers and attendees to promote the development of new collaborations and hasten the advancement of the field. Specific Aim 3 Provide a forum for junior investigators to interact with senior scientists. PUBLIC HEALTH RELEVANCE: It has only recently been appreciated that the immune and skeletal systems have major interactions. However, in the past, scientists who studied each of these disciplines often failed to fully appreciate the role of the other system. We believe that a primary way to enhance collaborations between scientists in these previously separate disciplines is to bring the members of both fields together at a conference in which all participants can interact freely and share ideas. Towards this goal, we will convene the Fourth International Conference on Osteoimmunology: Interactions of the Immune and Skeletal Systems at the Corfu Chandris Conference Center, Corfu, Greece from June 17-22, 2012.